| 摘要 |
PURPOSE:To precisely detect the window part position of postal matter by providing a curved part to an optical path consisting of a light source, a convex lens, a pinhole, an image photoelectric converter, and conveying pastal matter to the curved part. CONSTITUTION:An optical path consists of a spot light source 1, a convex lens 2, a pinhole plate 3 arranged at the imaging position of the light source, and an image photoelectric converter 4. When the size ratio of an object to be detected and the image photoelectric converter 4 is c:d, a point A where the ratio of a distance from the pinhole plate 3 and a distance between the pinhole plate 3 and image photoelectric converter 4 is c:d is selected. Then, the light source 1 and convex lens 2, and the pinhole plate 3 and image photoelectric detector 4 are slanted to a straight line 5 symmetrically on the point A'. In this state, when postal matter is conveyed in a plane 7 at right angles to the straight line 5, reflected light from the light source 1 strikes the image converting detector 4, detecting the presence, position, size, etc., of a window part. |
